York and Norkfolk, Nebraska
Department of Plant Agriculture

Day 5 - Thursday

Pioneer Hybrids & Green Plains Ethanol- York, Nebraska: Breeding, Biotechnology and Biofuels

(August 31, 2017)
By: Laura Scott, Ryan Schryver, Todd Frey, & Ben Morgan

Group photo in front of Pioneer Seed Processing Plant in York, Nebraska
Group Photo in Front of Pioneer Seed Processing Plant in York, Nebraska.

Further building on our previous day’s tours, today’s focus was going to be on corn breeding, uses and the technologies associated with that. We travelled to the Pioneer Hybrids Seed Processing Plant first, where we focused on the genetics and production of seed corn, as well as breeding for exclusive traits. The Green Plains Ethanol Plant was just down the road, and the focus here was biotechnology and biofuels use in North America.

We travelled from Lincoln, Nebraska to the Pioneer Hybrids seed processing plant located in York, Nebraska. When we arrived at the stop, we were welcomed by several Pioneer employees who gave a brief introduction of the day to day operations of Pioneer. We learned that the company was started in 1926 by Henry Wallace with a goal of helping farmers improve their crop production. Pioneer has since been acquired by Dupont and is now one of the leading producers of seed corn on a global scale. The company operates under four core values: safety and health, environmental stewardship, highest ethical behaviour, and respect for everyone. Pioneer accredits their successes to the way they treat their employees, as well as the services they provide to the farmers. This success is aided by technology to further improve products.

The York plant is the largest of Pioneer research facilities, apart from the headquarters in Johnston, Iowa. Currently, the company has 85 full time employees at this plant with many seasonal and part-time employees working during busier times of the year. The company grows roughly 2.5 million bushels of seed corn with 1.5 million bushels of this being shipped to other Pioneer plants. The plant processes the remaining one million bushels on site. Up to 80 hybrids are grown on approximately 30,000 acres each year, ranging from 95-120 day corn varieties. All of the corn is irrigated to compensate for lower annual rainfalls in Nebraska and ensure they receive a seed corn crop each year. Seed used at this processing plant is split with 25% white corn and about 75% yellow seed corn. All corn is grown on soybean ground to provide optimal ground conditions and avoid contamination from other varieties.

Following a presentation on the background of Pioneer, we were taught about the process of large scale seed production. Each hybrid is produced from pollination of a female inbred line by a male inbred line. The combination has been chosen previously in research plots over years of evaluations, based on the highest hybrid vigour (heterosis) and desirable performance of the hybrid. In large scale seed production, the female and male inbreds might be planted at different times, depending on the number of heat units each inbred requires to reach reproductive stage. This is done to synchronize pollination and silking in the male and female inbreds, respectively, for maximum productivity.  Often, for each row of male inbred line there are four rows of the female inbred line in between. This is called a 4-1 Growing Pattern. GPS guidance has greatly improved the success of planting male rows into growing female corn. Prior to pollination, the tassels are removed from the female plants and to aide pollination from the male plants, which are destroyed after pollination is completed. This allows for crossing of two inbred lines of corn to produce a superior hybrid that will exhibit hybrid vigour through selected traits and top genetics.

We then were given the opportunity to walk around the processing facilities. The entire facility was shown to us from the start, where their trucks unload seed corn to where it was packaged in bags or Proboxes for shipping. We saw things such as how husks are torn off the cobs, their drying facility, how kernels were sorted in terms of size, how it is treated with seed treatment, bagging machine, and their storage facility.

Following the tour, we were given an in-depth presentation by Ron Haarmann, who is the number one white corn plant breeder in the company. He gave a very detailed explanation on how corn breeding works. Most corn grown today is a hybrid. To produce a hybrid, two inbreeds must be crossed. Inbreds are produced by crossing a plant with itself for 7 generations to ensure genetic purity. This process usually takes seven years but can be reduced to 3.5 years by growing corn in South American during the winter to get two crops season. Finally, the cross of the two inbred lines results in a seed that will have higher seedling vigor and produce a completely uniform crop in the following year. The inbreds exhibit double haploid chromosomes for all ten chromosomes, where both halves of the chromosomes are exactly the same, resulting in a 100% pure inbred. Breeding is almost entirely a numbers game; from 2,000 hybrids, they may get one final hybrid that has the desired characteristics.

Green Plains Ethanol Plant
Our afternoon stop was at Green Plains in York, Nebraska. The facility was built in 1994 to produce ethanol, and was purchased by Green Plains in September of 2016. Mitch Sturh was both our tour guide and our guest speaker. Mitch’s role in the company is the plant manager. Green Plains is the second largest producer of ethanol in the world, with 17 plants in 8 different states across the Midwest. They also operate the fourth largest cattle feedlot in the U.S., at roughly 360,000 head annually. Recently, Green Plains acquired 8 vinegar production plants.

Annually, Green Plains processes 19 million bushels of corn, a majority of which is #2 yellow dent corn. This produces 56 million gallons of ethanol, 8,000 tons of corn oil, and 47,000 tons of distillers grain each year. The facility operates 24/7, barring no breakdowns or needs to shutdown (i.e., gas leak). Onsite, they have storage capacity for 1.2 million gallons of ethanol.  The location of the production facility is ideal for a number of reasons with main one being the proximity to the rail line and that the surrounding county (York County) produces an annual corn crop of 21 million bushels.

The facility can receive 16,000 bushels of corn per hour, with most of it arriving via truck. The corn must pass quality tests before it can be transferred into one of four storage bins. Each bin has the capacity to hold 80,000 bushels of grain. To begin the ethanol production process, corn is run through a hammer mill and turned into a fine powder with a consistency that is similar to flour. The corn flour is then mixed with water and cooked to 225°F. This gelatinizes and sterilizes the starch in the flour. The mixture is then pumped through the cook tube, where the temperature is dropped through a flashing process to a final temperature of 190°F. This process turns the starches into complex sugars. An enzyme mixture is then added to the mash and placed in a fermentation tank, converting the complex sugars into simple sugars. Next, yeast is added under anaerobic conditions to transform the simple sugars into CO₂ and alcohol. They then have to wait for the yeast to die off, before the mixture can be pumped into a Beerwell. At this time, the mixture is at a 15% alcohol level. Next, the mixture is distilled to 95% alcohol and the remaining water is removed through a dehydration process to ensure the final product is 100% alcohol. It takes 65 hours from start to finish to turn a bushel of corn into 2.80 gallons of ethanol and 15 pounds of distillers grains.

Ethanol plants can process four different grades of alcohol; Grain Neutral Spirits, Food Chemical Codex Grade, Industrial Grade, and Fuel Grades. This particular plant produces both fuel and industrial grade alcohols; however, a majority of the production is fuel grade alcohols. The only difference between Industrial and fuel alcohol is that fuel alcohol is denatured. This process adds 5% gasoline to ensure that fuel grade alcohol cannot be used for human consumption.

The other major by-product of ethanol production is distillers grains. They are typically 28% protein and 8-10% fat, depending on the batch of ethanol. This facility produces both wet and dry distillers grains. Wet distillers grains are dried using hot air forced through a tumble dryer to remove excess moisture. Both products are commonly used in cattle feedlot rations. 

This past summer, the global ethanol market was heavily over supplied, and prices were weak, leading Green Plains to shut down nine of their production plants for almost a month. This pulled 60 million gallons of ethanol off the market, which allowed the price to rebound. The York location did not shut down over this time. We also learned that because most of their ethanol production is transported through the Gulf of Mexico, Hurricane Harvey has made it impossible to move any product internationally. The Texas oil industry is also at a standstill further slowing the availability of product. According to Mitch, Green Plains will not have any more storage available within a week if transportation cannot resume.

Both tours focused on corn production in every stage, right from the development of the seed variety to the final alcohol product that consumers encounter. The stops built on each other, in that Pioneer gave us a detailed glance into both the genetic evolution and the future of corn breeding, seed production and the extensive research that goes into each variety. Green Plains really added to the seed production stop, as it showed us what a lot of the corn harvested in North America is used for. Everyone appreciated how both tours gave some science as well as some business, making it relatable to students from varying programs.